The present invention relates generally to the field of defragmenting, and more particularly to shifting a defrag operation in a mirrored system.
In today's data storage environments, operations against storage volumes, also referred to as a hard disk drives (HDD), require multiple passes of disk reads and writes. A single hard disk usually consists of several platters. Each platter has the same number of tracks, and a track location that cuts across all platters is called a cylinder.
Disk reads/writes are performed by disk read/write heads that are the small parts of a disk drive that move above the disk platter and transform the platter's magnetic field into electrical current reading or writing to the disk. An example of disk read/writes would be a volume defragmentation (DEFRAG). In the maintenance of file systems, defragmentation is a process that reduces the amount of fragmentation by physically organizing the contents of the storage device into the smallest number of contiguous regions (i.e., fragments). The defragmentation process also attempts to create larger regions of free space using compaction to impede the return of fragmentation. Some defragmentation utilities try to keep smaller files within a single directory together, as they are often accessed in sequence.
Many known data storage systems use mirrored volumes. In data storage, disk mirroring is the replication of logical disk volumes onto separate physical hard disks in real time to ensure continuous availability. A mirrored volume is a complete logical representation of separate volume copies.